mulitple monitor question please help

i have been using a matrox g450 with 4 monitors for 5 months now. No problems. but i just moved and when i tried to hook them back up. I can only get 2 monitors to work. I remember having problems when i first put in the new card. but i cant figure out what i did to get all 4 monitors working at one time. when i go to settings I only see 2 monitors and the drop down menu only lists 2 monitors....I have tried everything...can't seems to get it to work...I seem to remember that it was something simple that I did ...like just checking or uncheck some box...please help i am going crazy